Method for making templates and the like



G. B. CROUSE ,METHOD FOR MAKING TEMPLATES AND THE LIKE Filed July a.1941 April 3, 1945.

Patented Apr. 3, 1945 METHOD Foa George B.

by mesne asslgnmen poration, New York, N. Y.,

York

MAKING TEMPLATES AND THE LIKE Crouse, East Setauket, N. Y., assignor,

ts, to Photo-Positive Cora corporation of New Application July 8, 1941,Serial No. 491,440

6 Claims.

The present invention relates particularly to an improved method forreproducingV drawings on blanks to facilitate their manufacture intovarious articles..

The time required for making accurate scale drawings of parts forairplanes and other equipment occasions delays in the manufacturethereof land increases their cost. The present invention is asimplification of the methods heretofore used and a reduction in thetime required and the cost of reproducing the drawings on blanks fortemplates'and the like. Heretofore, the general practice has been tomake scale drawings on the drafting board first and thereafter to copyover manually the scale drawings onto the template or other lpart to bemanufactured. The time required is substantial and the chances of errorsincrease with the complication of the drawings, requiring numerous4checking operations. In spite of all precautions, some errors areoverlooked resulting in additional cost and loss of time in re-makingparts and drawings.

The present invention aims to overcome or minimize the above and otherobjections and difficulties by providing an improved, relatively simplemeans and method for transferring reproductions of drawings to blanksadapted to be used for making templates, patterns and the like.

An object of the present invention is to reduce the time required forproviding accurate scale drawings on blanks for templates and otherparts tobe manufactured.

Another object of the invention is to simplify the manufacture ofairplane parts.

Another object of the invention is to provide a simple method whicheliminates errors in the transfer of original scale drawings to atemplate or the like without impairing in the reproduction the accuracyof the dimensions in the original scale drawings.

been chosen for purposes of illustration and description and is shown inthe 'accompanying drawing, forming a part of the specification, whereinFig. 1 is a perspective view of a simple drawing on a rigid backingwhich prevents any material variations in the dimensions thereof;

Fig. 2 is a perspective view of the preferred 'embodiment oflight-sensitive material for use Another object of the invention is toprovide an improved method utilizing a light-sensitive film having areinforcing backing adapted to retain the dimensional characteristicsthereof during exposure and adapted to be removed after the exposed filmis applied to a blank for a template.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

A preferred embodiment of the invention has in the method;

Fig. 2a is a fragmentary sectional view greatly enlarged and exaggeratedto show the +-vpe and character of the laminatons of the composite sheetshown in Fig. 2.

Fig. 3 is a diagrammatic view showing the exposure of thelight-sensitive material to reproduce the drawing of Fig. 1 thereon.

Fig. 4 is a perspective view showing the exposed sheet of Fig. 2 adheredto a template with the reinforcing backing being removed.

Fig. 4a is an exploded view of the composite sheet of Fig. 2 adhered toa template with the reinforcing backing removed.

Fig. 5 is a fragmentary sectional view illustrating another embodimentof light-sensitive material.

Referring again to the drawing and more particularly to Fig. 1, there isshown a ybacking I of metal, glass or other suitable rigid material. Alacquer or other coating 2 is preferably applied to one surface of thebacking to facilitate the making of a drawing 4 thereon. Paper securedto the backing by a suitable adhesive gives excellent results, but alacquer or other coating may be utilized. The drawing 4 is accuratelymade to scale so that it may be reproduced on a blank and a template orother device made therefrom by cutting along the lines of the drawing.Heretofore it has been customary for a draftsman to reproduce, with theusual drafting instruments. the drawing shown in Fig. 1 on the surfaceof a template blank. Thereafter, the drawing had to be checked to avoiderrors; the template was then formed by cutting away those portionsindicated on the drawing. The drawing must be made accurately to scaleon the template in order to have the part the proper size and in orderto have the rivet holes and other irregularities agcurately in positionto t with cooperating parts in the manufacture of the airplane ormachine. In addition, a separate drawing had to lbe made on templateblanks for eachV template required.

The present method contemplates the reproduction photographically of thedrawing shown blank shown in Fig.

duction is made 4 without material distortion of any of the scaledportions. In doing this, applicant provides a light-sensitive sheet ofmaterial 5 shown generally in Fig. 2 and shown in detail in Fig. 2a. Thepreferred embodiment of material comprises a sheet of relatively tough,smooth paper 6 coated with superimposed layers of a moisture resistingand water insoluble lacquer 1, a light-sensitive emulsion 3 of anysuitable composition, for example, a gelatin-silver halide emulsion, anda protective layer or bonding layer 8 which may be made of collodion ora similar material.

Preferably the layer 8 forms a water resistant surface over theemulsion. The protective or bonding layer 8 may bevomitted in certaininstances but its use is preferred as the lightsensitive layer is thusenclosed between waterproof or water resistant layers. This prolongs thelife of the light-sensitive layer.

In order to reproduce the drawing on the lightsensitive material shownin Figs. 2 and 2a the material is placed over the drawing shown in Fig.1 with the protective or bonding layer 8 contacting the drawing. Asuitable plate 9 of opal glass or the like may be placed over the sheetof material 5 to assist in holding it rmly and evenly against thedrawing. A light source I0 of any suitable type may be utilized forproducing a reflex print on the light-sensitive sheet 5. In view of thefact that only the protective-or bonding layer 8 separates the drawing 4from the light-sensitive emulsion 3, a contact print is obtained whichmust be accurate in `all details. If the backing I for the drawing 4 ofFig. 1 is made of glass or other transparent or translucent material,the light I0 may be placed under the backing I to allow light rays topass through the drawing 4 in obtaining a photographic reproduction onthe light-sensitive material 5.

Preferably, the atmosphere in the room where the exposure is made andwhere the light-sensitive material is kept, is air-conditioned to avoidany contraction or expansion thereof. In order to guard further againstcontraction and expansion, the light-sensitive material is applied tothe template blank immediately after exposure, allowing as little timeas reasonably possible for any changes to take place. In order to effectthis transfer the template blank, guide or pattern Il shown in Figs. 4and 4a is provided with an adhesive coating I2 which preferably is ofthe type described hereinafter. The light-sensitive material is appliedto the template II with the protective or bonding surface y8 facingdownwardly in contact with the adhesive I2. Suitable heaty and a vacuumpad such as that illustrated in Fig. 9 of my prior applicationidentified above may be utilized in securing the two together.Thereafter the paper IiY islstripped off and carries with it the lacquercoating 1, as shown more particularly in Fig. 4a. The stripping off' ofthe paper leaves the'light-sensitive emulsion exposed and adhered tothetemplate II. Since the template blank II is of rigid material itprevents distortion of the emulsion. While thus supported onthe surfaceof the template blank the emulsion thereon may be processed anddeveloped to reproduce the drawing 4 thereon. Since the processingoperations, which require the use of liquids, are done after thelight-sensitive material is secured to the template blank, distortion isminimized or completely prevented. Since the reprowhile the drawing andlightsensitive sheet of material are in contact, there is no opportunityfor distortion in the reproducing operation. No lenses are required andno distances have to be measured. Hence, the usual errors of photographyare avoided.

While in the preferred embodiment where the drawings are to bereproduced on a. template blank, it is preferred to apply the adhesivecoating I2 to the template surface, the adhesive coating may be appliedto' the light-sensitive material. Fig. 5 illustrates the coating I2asoapplied. The light-sensitive material is identical with that shown inFig. 2a, except that the adhesive I2a is added onto the bonding layer 8.When the light-sensitive material is applied to the template blank, thepaper 6 and the lacquer coating 'I are stripped off in the same manneras shown in Fig. lla.

By applying adhesive to the metal plate or template blank as shown inFigs. 4 and 4a, a coating may be utilized which is permanently tacky.This will permit the light-sensitive material to be adhered or bonded tothe template blank in a vacuum or other suitable place without theapplication of heat. While this construction is not as desirable as onebonded with heat, it is simpler and gives satisfactory results for manypurposes.

'I'he adhesive used on the template blank II should meet certainrequirements. The adhesive should retain its properties when subjectedto the action of processing solutions and the bond formed thereby shouldbe strong enough to withstand the stresses set up by the wetting. Theadhesive also should soften at a relatively low temperature when thepaper or a light-sensitive emulsion is applied in order to avoid usingtemperatures sumciently high to impair `the lightsensitive emulsion. Inaddition, the adhesive should not soften at the temperatures created inthe metal plate by machining and grinding operations. The latter may runup as high as 475 degrees Fahrenheit. The preferred embodiment ofadhesive utilizes a thermo-plastic adhesive whose softening pointincreases after the rst application of heat. This result may be achievedby adding to the adhesive a volatile plasticizer which will not beappreciably volatilized by the temperature of the air used to remove thecoating solvents. Thev presence of the plasticizer serves to lower thesoftening point of the plastic at the I'lrst heating, where asubstantial portion of the plasticizer will be volatilized so that,thereafter, a temperature substantially higher, such as 475 degreesFahrenheit will be required to soften the material. while there is nointention of niitmetal blank by flowing it evenly over the surface anddrying.

By utilizing a vacuum press it is possible to apply the sheet ofmaterial to a template blank without wrinkles in it. In this way, asmooth surface is obtained which avoids any irregularities in the nishedreproduced drawing.

In the operation of the method, the draftsman rst makes a scale drawingon a surface 2 on a asvavev 3 backing I. Thereafter the light-sensitivematerial shown in lligs. 2 and 2a is applied with the protective orbonding layer adjacent the drawing and with the paper C at the sideremote from the drawing. A contact print is made by renex printing or byhaving the backing plate I made of a transparent material and allowingthe light rays to pass through it. If desired, a type of emulsion may beutilized-which produces a positive instead of a negative in the reflexprinting.l Immediately after the exposure the light-sensitive materialis adhered to the template blank Il by the adhesive l2, preferably byutilizing a vacuum.

press such as illustrated in my prior application. The paper 6 and thelacquer coating 1 are then stripped of! from the emulsion, leaving theemulsion and the bonding layer adhered to the tem plate blank I I,through the intermediation of the adhesive I2. The emulsion is thus heldfirmly in place against distortion of any kind and is ready to besubjected to the processing, developing and fixing solutions, afterwhich the drawing 4 will be reproduced accurately on the template. Thetemplate blank then may be cut away or ground away, using the reproduceddrawing as a guide, in order to produce a finished template. y

It will be seen that the present invention provides an improved methodof reproducing drawings on template blanks without loss of accuracy andin minimum time. A single sheet of lightsensitive paper is sufficient totransfer a drawing onto a template blank. Since the exposedlightsensitive material is turned over, the reproduction of the drawingwhich appears on the template blank is not a reversed or mirror imagebut an actual positive reproduction of the original drawing. By using asuitable emulsion, the black and white may likewise be reproduced asupon the original drawings without being reproduced as negatives,although in most cases the reverse of the black and white portions arenot objectionable. The reproduction is done without lenses by having thesurfaces in actual contact which increases the accuracy and simplifiesthe operation. The final reproduction is adhered to the template With anadhesive capable of withstanding the high temperatures to which it maybe subjected. The present method simplifies the operations and hasunusual advantages with various types of work. Sheets of the preferredor modified material which carry the light-sensitive layer may bereadily cut, packed and stored, or the material may be supplied inrolls. It is not necessary to take any extraordinary precautions inexposing the light-sensitive layer carried by the material.

As various changes may be made in the form, construction and arrangementof the parts herein without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in e, limiting sense.

Having thus described my invention, I claim:

l. The method of making templates, patterns and the like, whichcomprises applying an overcoating of material suitable for receiving adrawing to a relatively rigid surface, making a drawing on said coating,applying a water-proofing lacquer to a sheet of paper, securing alight-sensitive surface to the lacquered side of said sheet of paper,placing said drawing and said light-sensitive surface substantially incontact, transferring a reproduction of the drawing to thelight-sensitive surface while they are superimposed, adhesively securingsaid iight-sensitive surface to a template blank or the like immediatelyafter exposure by a thermoplastic adhesive, which does not requirewetting and which requires a highertemperature to soften Aafterapplication by heat than before,

with the exposed side thereof facing the blank, the transfer of thereproduction of the drawing to the light-sensitive surface and thesecuring of the light-sensitive surface to the blank being performed inan air conditioned atmosphere to prevent dimensional changes therein,thereafter processing said light-sensitive surface adhered to thetemplate to develop and ilx said reproduction of the drawing thereon andshaping said blank in accordance with the reproduction thereon toproduce a template.

2. The method of making templates, patterns and the like. whichcomprises making a drawing on a relatively rigid surface, applyingwaterproong lacquer to a sheet of paper, securing a light-sensitivesurface to the lacquered side of said sheet of paper, applying waterresistant coating over said light sensitive surface, placing saiddrawing and said light-sensitive surface with the coating thereover incontact, transferring a reproduction of the drawing while they aresuperimposed, adhesively securing said coated lightsensitive surface toa template blank or the like, prior to wetting, by means of athermoplastic adhesive with the exposed side thereof facing the blank,removing the paper from said light-sensitive surface leaving thelight-sensitive surface adhered to the template blank, processing saidlight-sensitive surface to develop and fix said reproduction of thedrawing thereon and shaping said blank in accordance with thereproduction thereon to obtain .a template,

3. The method of making templates and the like, which comprises securinga sheet of paper or the like suitable for receiving a drawing to arelatively rigid backing material, making a drawing on said sheet ofpaper, placing said drawing and a stiffened light-sensitive surfacesubstantially in contact, transferring a reproduction of said drawing tosaid stiffenedsensltized surface,

adhesively securing said stiffened sensitized surface to a templatesheet or the like, immediately after exposure, by a thermoplasticadhesive, which does not require wetting and which requires a highertemperature to soften after application by heat than before to preventdimensional changes therein, the exposed side of the sensitized surfacefacing the template sheet and thereafter processing said sensitizedsurface on the template sheet to develop and `fix the reproduction ofsaid drawing thereon to minimize dimensional changes in thereproduction.

4. The method of making templates and the like, which comprises applyinga coating material suitablefor receiving a drawing to a relatively rigidsurface, making a drawing on said coating. placing said drawing and alight-sensitive surface substantially in contact, said light-sensitivesurfacel being on one side of a backing member. transferring areproduction of said drawing to said sensitized surface, adhesivelysecuring said sensitized surface to a template sheet or the like,immediately after exposure, by a thermoplastic adhesive, which does notrequire wetting l and which requires a higher temperature to cordancewith the reproduction template sheet. to develop and nx the reproductionof said drawing thereon to minimize dimensional changes in thereproduction.

5. The method of making templates and the like which comprises securinga sheet of paper or the like suitable for receiving a drawing to arelatively rigid surface, making a drawing on `said sheet of paper,placing said drawing and a light-sensitive surface applied to a backingsubstantially in contact, transferring a reproduction of said drawing tosaid light-sensitive surface, adhesively securing said sensitive surfaceto a template sheet or the like, prior to wetting by a 6. The method ofmaking templates andthe like, which comprises applying a coatingmaterial suitable for receiving a drawing to a relatively rigid surface,making a. drawing on said coating material, placing said drawing andiight-sensitive surface applied to a backing member substantiallyincontact, transferring a reproduction of said drawing to said sensitizedsurface, adhesively securing said sensitized surface to a template sheetor the like prior to wetting by a thermoplastic adhesive, which does notrequire wetting and which requires a higher temperature to soften afterapplication by heat .than before to rprevent dimensional changestherein, the exposed side of the sensitized surface facing the templatesheet, stripping the backing member from the sensitized surface,thereafter processing said sensitized surface on the template sheet todevelop and fix the reproduction of said drawing thereon to minimizedimensional changes in the reproduction, and shaping said blank inaccordance with the reproduction thereon to produce a template.

GEORGE B. CROUSE.

